Lab results are great, but most contractors want to see exactly how a new process works in the field before accepting it as standard. Recently, Prairie experts helped two leading Wisconsin companies put our Aridus® floor system through its paces to see how it performs – even when the unexpected happens.

Project leaders at C.G. Schmidt chose Aridus for a side room near a high-school gymnasium they were building in Milwaukee. The 12’ x 40’ slab-on-grade surface would ultimately be covered with vinyl sheeting, says Director of Field Operations Mark Schmidt.

“Vinyl is impervious and traps any moisture that rises up, resulting in a bubbled floor,” Schmidt explains. To prevent failure, flooring subcontractors can demand that topical applications be used when slabs don’t reach the specified relative humidity (RH) on time, “which tacks anywhere from $1.50 to $10 per square foot onto our costs, usually very late in the construction cycle. You can see why a reliable, fast-drying alternative sounded good to us.”

The downpour after the pour

Schmidt needed proof positive that the 5-inch slab had reached 80% RH or less before flooring could be laid. “This wasn’t a dry environment, which is typical of most slabs we place,” he says. “But then a sudden rainstorm flooded the area, thanks to a roof conductor that hadn’t been properly tied off. We had standing water on the surface for a full day.”

At first Schmidt doubted the slab would make its numbers. But tests by Giles Engineering of Waukesha showed great results at just 28 days. “Only one probe showed RH over 85%, and that was due to a damaged probe cover,” Schmidt says. “We replaced it and it came in under 80%. By 45 days we had RH of 69% to 73% — and the flooring guys were ready to go.”

Ready in 30? Mortenson’s time test

When Mortenson Construction faced a tough deadline for stadium renovations that called for rubber coatings over a concrete floor, they felt Aridus might solve their dilemma.

“We couldn’t start construction until mid-November, with a turnover date in late February,” says Mortenson Senior Superintendent Doug Hills. Crews would pour the 1,700-square-foot floor on an elevated metal deck to a depth of 6.5 inches. To meet deadlines, the slab would need to reach less than 85% RH within 30 days.

“We knew Aridus would fit the bill,” says Mike Fiorita, sales manager for Prairie Wisconsin. “But this is a highly specialized mix, and batching, pouring and placement require strict quality control. We worked closely with Mortenson on this job, as we do with all our contractors to ensure their success with Aridus.”

Great support, surprising results

QC Manager Sergio Martinez organized a pre-pour meeting with Mortenson finishers to explain the properties of the proprietary mix. Then he carefully reviewed placement instructions with Prairie drivers the day before the pour to make sure everyone understood the requirements.

“The mix pumped well and finished well with Confilm,” says Hills. Because of the slab’s location and size, the surface was hand-struck, but crews were off the floor in 8 hours.

Tests by Mortenson and Giles Engineering far exceeded the target RH, ranging from 62% to 67% at 28 days. “We were surprised to see the 7-day breaks come in at 8,400 psi,” Hills adds. High early strength is a byproduct of Aridus’ unique mix design, notes Martinez. “The 28-day results came in at 10,000 psi,” he says.

Two thumbs up

Both Schmidt and Mortenson plan to use Aridus on future projects. “Anything with tight time constraints, like a lot of the remodeling we do, would benefit from this mix,” Hills says. “We’re considering it for hospital projects where flooring specs call for vinyl coverings.”

“This is a great option to offer owners,” Mark Schmidt says. “Aridus costs more, but it cuts drying time significantly and reduces the uncertainty built into the process. That’s an advantage we feel pays for itself.”

Want to try Aridus for your next interior flooring project? Contact our ​flooring experts for details and pricing now.​

Why it works

As water-based adhesives become the standard for most floor coverings, moisture specs for underlying slabs get tougher. The Aridus rapid-dry concrete system, available only from Prairie Material, gets floors to spec within 45 days or less. But this self-desiccating mix is radically different from traditional methods that encapsulate water. Prairie sales and QC teams work closely with contractors and lead finishers, especially the first time they try Aridus. “This mix does what it promises,” says contractor Mark Schmidt, who calls his first placement “a real-world test” Aridus passed with flying colors.